New policy protobuf protocol.

chrome/browser/policy/cloud_policy_cache.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_POLICY_CLOUD_POLICY_CACHE_H_
+#define CHROME_BROWSER_POLICY_CLOUD_POLICY_CACHE_H_
+
+#include <string>
+
+#include "base/file_path.h"
+#include "base/gtest_prod_util.h"
+#include "base/ref_counted.h"
+#include "base/scoped_ptr.h"
+#include "base/synchronization/lock.h"
+#include "base/time.h"
+#include "chrome/browser/policy/configuration_policy_provider.h"
+#include "chrome/browser/policy/proto/device_management_backend.pb.h"
+#include "policy/configuration_policy_type.h"
+
+class DictionaryValue;
+class ListValue;
+class Value;
+
+using google::protobuf::RepeatedPtrField;
+
+namespace policy {
+
+namespace em = enterprise_management;
+
+// Keeps the authoritative copy of cloud policy information as read from the
+// persistence file or determined by the policy backend. The cache doesn't talk
+// to the service directly, but receives updated policy information through
+// SetPolicy() calls, which is then persisted and decoded into the internal
+// Value representation chrome uses.
+class CloudPolicyCache {
+ public:
+  typedef ConfigurationPolicyProvider::PolicyMapType PolicyMapType;
+
+  explicit CloudPolicyCache(const FilePath& backing_file_path);
+  ~CloudPolicyCache();
+
+  // Loads policy information from the backing file. Non-existing or erroneous
+  // cache files are ignored.
+  void LoadPolicyFromFile();
+
+  // Resets the policy information. Returns true if the new policy is different
+  // from the previously stored policy.
+  bool SetPolicy(const em::CloudPolicyResponse& policy);
+  bool SetDevicePolicy(const em::DevicePolicyResponse& policy);
+
+  // Gets the policy information. Ownership of the return value is transferred
+  // to the caller.
+  DictionaryValue* GetDevicePolicy();
+  const PolicyMapType* GetMandatoryPolicy() const;
+  const PolicyMapType* GetRecommendedPolicy() const;
+
+  void SetUnmanaged();
+  bool is_unmanaged() const {
+    return is_unmanaged_;
+  }
+
+  // Returns the time at which the policy was last fetched.
+  base::Time last_policy_refresh_time() const {
+    return last_policy_refresh_time_;
+  }
+
+  // Returns true if this cache holds (old-style) device policy that should be
+  // given preference over (new-style) mandatory/recommended policy.
+  bool has_device_policy() const {
+    return has_device_policy_;
+  }
+
+ private:
+  friend class CloudPolicyCacheTest;
+  friend class DeviceManagementPolicyCacheDecodeTest;
+
+  // Decodes a CloudPolicyResponse into two (ConfigurationPolicyType -> Value*)
+  // maps and a timestamp. Also performs verification, returns NULL if any
+  // check fails.
+  static bool DecodePolicyResponse(
+      const em::CloudPolicyResponse& policy_response,
+      PolicyMapType* mandatory,
+      PolicyMapType* recommended,
+      base::Time* timestamp);
+
+  // Returns true if |certificate_chain| is trusted and a |signature| created
+  // from it matches |data|.
+  static bool VerifySignature(
+      const std::string& signature,
+      const std::string& data,
+      const RepeatedPtrField<std::string>& certificate_chain);
+
+  // Returns true if |a| equals |b|.
+  static bool Equals(const PolicyMapType& a, const PolicyMapType& b);
+  // Helper function for the above.
+  static bool MapEntryEquals(const PolicyMapType::value_type& a,
+                             const PolicyMapType::value_type& b);
+
+  // Decodes an int64 value. Checks whether the passed value fits the numeric
+  // limits of the value representation. Returns a value (ownership is
+  // transferred to the caller) on success, NULL on failure.
+  static Value* DecodeIntegerValue(google::protobuf::int64 value);
+
+  // Decode a GenericValue message to the Value representation used internally.
+  // Returns NULL if |value| is invalid (i.e. contains no actual value).
+  static Value* DecodeValue(const em::GenericValue& value);
+
+  // Decodes a policy message and returns it in Value representation. Ownership
+  // of the returned dictionary is transferred to the caller.
+  static DictionaryValue* DecodeDevicePolicy(
+      const em::DevicePolicyResponse& response);
+
+  // The file in which we store a cached version of the policy information.
+  const FilePath backing_file_path_;
+
+  // Protects both |mandatory_policy_| and |recommended_policy_| as well as
+  // |device_policy_|.
+  base::Lock lock_;
+
+  // Policy key-value information.
+  PolicyMapType mandatory_policy_;
+  PolicyMapType recommended_policy_;
+  scoped_ptr<DictionaryValue> device_policy_;
+
+  // Tracks whether the store received a SetPolicy() call, which overrides any
+  // information loaded from the file.
+  bool fresh_policy_;
+
+  bool is_unmanaged_;
+
+  // Tracks whether the cache currently stores |device_policy_| that should be
+  // given preference over |mandatory_policy_| and |recommended_policy_|.
+  bool has_device_policy_;
+
+  // The time at which the policy was last refreshed.
+  base::Time last_policy_refresh_time_;
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_CLOUD_POLICY_CACHE_H_